A free showing of “12th and Clairmount” is planned at Campus Martius Park in downtown Detroit.

The Downtown Detroit Partnership says the documentary will be shown at 8 p.m. today and viewers should arrive early.

The film, which premiered earlier this year with four sold-out screenings during the Freep Film Festival, looks back at the 1967 Detroit riot/rebellion, its causes and aftermath. Vintage home movie footage from metro Detroiters provides the heart of the film.

Sunday was the 50th anniversary of the start of the five-day riot which followed a police raid on an illegal after-hours’ club. The riot left 43 people dead, dozens injured and more than 1,400 buildings burned.

Many in the community blamed frustrations blacks felt toward the mostly white police force and city policies that pushed families into overcrowded neighborhoods.